Carson FlashShield Kill Flash ARD Anti-Reflective Lens Device (BX-42) The FlashShield is An Anti-Reflective Lens Device Easily Clips On To Most Full-Sized Binoculars and Riflescopes (32mm to 43mm Objective Lens Diameters) Blocks Reflections Off Lenses | Lightweight and Easy to Use Helps Reduce Glare | Great for Hunting and Wildlife Viewing Backed by Carson's Limited Lifetime Warranty